After-hours doctors referred over claims

A provider of urgent after-hours doctors is being investigated for fraud, a Senate committee has been told.

Officials from the Health Department told senators that 28 of the top 29 claimants have been interviewed, with five providers referred to the Professional Services Review, as of Wednesday morning.

"The investigation is ongoing," first assistant secretary Simon Cotterell told the hearing in Canberra.

"One provider is being investigated for fraud. I can't give you more details on that."

Health Minister Greg Hunt last year called for an inquiry into the after-hours sector after concerns about the claiming of subsidies for call-outs, including for visits which were classified as "urgent" but pre-booked.

Also in December the minister announced changes to rebates, including not paying the top Medicare rate for trainee doctors.

From Thursday the rebate for doctors undertaking home visits falls from $129.80 to $100.